1. Field of Invention
The invention pertains to the area of mechanical metal-working and deals, in particular, with a method of manufacturing long forgings from ingots and continuous cast billets.
This method can be used in machine building and metallurgy for manufacturing long products like rods, columns, shafts and so on; manufacturing pre-forged intermediate products from special, stainless, heat-resistant and hard-wrought alloys to be later worked mechanically into rods; pre-forging of long workpieces from the above mentioned alloys for subsequent mechanical dividing into uniform parts and also for forging conventionally cast ingots and continuous cast billets into deformed ones.
2. Description of the Related Art
There's known a method of radial forging of ingots and continuous cast billets with the help of a radial forging machine (see, for instance, an advertisement leaflet of "SMS" company "Radial forging machine. Advanced extrusion and forging technology". P/327. SMS Hasenclever, 3000/4/90 Sch.). By this method the initial blank is heated first, then it is set up into the chuck head of a manipulator and after that fed into the interspace of the forging tools, being simultaneously rotated for producing forgings of round cross-sections while without rotation forgings of square or rectangular cross-sections are obtained. The blank is swaged at the same part along its length in the working zone, in turn by each pair of forging tools moving radially in one plane to the blank's axis. During the intervals between swagings, when the forging tools accomplish their back travel, the blank is moved in the axial direction, when forgings of square and rectangular cross-sections should be obtained, or the blank is rotated around its longitudinal axis and moved lengthwise when forgings of round cross-sections should be obtained. The mentioned above operational cycle is repeated over and over reducing the blank to the required sizes. The considered forging method makes it possible to obtain the deformation of cast metal structure mainly in the axial zone of the forging.
However, when using the mentioned above known method of radial forging, there occasionally takes place the opening of cavities of shrink origin in ingots or continuous cast billets in their axial zones at the stage of swaging. In addition, the area reduction in the blank is 5:1. This requires an initial billet with a cross-sectional area five times larger than the cross-sectional area of the forging.
In accordance with another method of forging ingots and continuous cast billets with the help of a radial-swaging machine (see, for instance, an advertisement leaflet of "Danieli" company "New forging installations with Danieli hydraulic forging machines", Oct. 15, 1987, AD/f6) the initial conventionally cast ingot or continuously cast billet is heated first, then it is set up into the chuck head of a manipulator and after that fed into the interspace of the forging tools, being simultaneously rotated for producing forgings of round cross-sections and fed without rotation for producing forgings of square or rectangular cross-sections. The working interspace is formed by four forging tools. The forging tools move radially in one plane toward each other to the billet's axis. In addition, the forging tools move in the same tangential direction. The mentioned forging tools swage the blank simultaneously at one portion of its length. During the intervals between swagings, when the forging tools accomplish their back travel, the blank is rotated around its longitudinal axis and moved lengthwise, for forming forgings of round cross-sections, or just moved lengthwise, for forming forgings of square and rectangular cross-sections. The mentioned above operational cycle is repeated over and over swaging the blank lengthwise to the required sizes. The considered forging method makes it possible to obtain a forging with dense metal macrostructure in its axial zone and the deformation of cast metal structure mainly in its surface zone.
However, when using the mentioned above known method of forging the forging ratio is 3:1. This requires having an initial blank with a cross-sectional area three times larger than the cross-sectional area of the forging.
Thus, none of the existing known radial forging methods give an opportunity to obtain a forging with dense metal macrostructure both in its surface and axial zones with the forging ratio less than 3:1.